Systems and methods for invalidating directory of non-home locations ways

Patent metadata

Field	Value
Publication number	US-2016110293-A1
Application number	US-201414515345-A
Country	US
Kind code	A1
Filing date	Oct 15, 2014
Priority date	Oct 15, 2014
Publication date	Apr 21, 2016
Grant date	—

Abstract

Systems and methods for invalidating a way of a directory for non-home locations (DNHL) set that stores an identifier of a home location of an address is disclosed. As a part of a method, a request to store data in a location of a special cache that is being tracked by the way of the DNHL set is accessed, it is determined if an address stored in the location of the special cache is stored in a non-home location, a DNHL set is identified that tracks the location of the special cache if the address is not stored in a non-home location, and a set and way of the location of the special cache is compared with a set and way identifier stored in each way of the DNHL set. The way of the DNHL set that stores a matching set and way identifier is invalidated.

First claim

We claim:

1 . A method for invalidating a way of a directory of non-home locations (DNHL) that stores an identifier of a home location of an address, comprising:
accessing a request to store data in a location of a special cache that is being tracked by said way of said DNHL; determining if an address stored in said location of said special cache is stored in a non-home location; if said address is not stored in a non-home location, identifying a set in said DNHL that tracks said location of said special cache; comparing a set and way of said location of said special cache with a set and way identifier stored in each way of said set of said DNHL; and if a matching set and way identifier is found in a way of said set of said DNHL, invalidating a way of said set of said DNHL that stores said matching set and way identifier.

2 . The method of claim 1 wherein said determining if an address stored in said location of said special cache is stored in a non-home location comprises examining a bit in a cache line that comprises said address.

3 . The method of claim 1 wherein said identifying determines a set of said DNHL that is designated to track a set of said special cache that contains said location of said special cache.

4 . The method of claim 1 wherein said invalidating frees said way of said set of said DNHL to store data.

5 . The method of claim 1 wherein said set and way identifiers identify a set and a way of said special cache.

6 . The method of claim 1 wherein said special cache stores addresses in home and non-home locations.

7 . The method of claim 1 wherein each set of said non-home location directory comprises a plurality of ways.

8 . A processor system, comprising:
processing components; and cache controlling components, wherein said cache controlling components comprise a system for invalidating a way of a directory for non-home locations (DNHL) that stores an identifier of a home location of an address, comprising: an accessing component for accessing a request to store data in a location of a special cache that is being tracked by said way of said DNHL; a determining component for determining if an address stored in said location of said special cache is stored in a non-home location; an identifying component for, if said address is not stored in a non-home location, identifying a set in said DNHL that tracks said location of said special cache; a comparing component for comparing a set and way of said location of said special cache with a set and way identifier stored in each way of said set of said DNHL; and an invalidating component for, if a matching set and way identifier is found in a way of said set of said DNHL, invalidating said way of said set of said DNHL that stores said matching set and way identifier.

9 . The system of claim 8 wherein said determining if an address stored in said location of said special cache is stored in a non-home location comprises examining a bit in a cache line that comprises said address.

10 . The system of claim 8 wherein said identifying determines a set of said non-home location directory that is designated to track a set of said special cache that contains said location of said special cache.

11 . The system of claim 8 wherein said invalidating frees said way of said set of said DNHL to store data.

12 . The system of claim 8 wherein said set and way identifiers identify a set and a way of said special cache.

13 . The system of claim 8 wherein said special cache stores addresses in home and non-home locations.

14 . The system of claim 8 wherein each set of said DNHL comprises a plurality of ways.

15 . A cache controller that comprises a system for invalidating a way of a directory for non-home locations (DNHL) that stores an identifier of a home location of an address, comprising:
an accessing component for accessing a request to store data in a location of a special cache that is being tracked by said way of said DNHL; a determining component for determining if an address stored in said location of said special cache is stored in a non-home location; an identifying component for, if said address is not stored in a non-home location, identifying a set in said DNHL that tracks said location of said special cache; a comparing component for comparing a set and way of said location of said special cache with a set and way identifier stored in each way of said set of said DNHL; and an invalidating component for, if a matching set and way identifier is found in a way of said set of said DNHL, invalidating said way of said set of said DNHL that stores said matching set and way identifier.

16 . The cache controller of claim 15 wherein said determining if an address stored in said location of said special cache is stored in a non-home location comprises examining a bit in a cache line that comprises said address.

17 . The cache controller of claim 15 wherein said identifying determines a set of said non-home location directory that is designated to track a set of said special cache that contains said location of said special cache.

18 . The cache controller of claim 15 wherein said invalidating frees said way of said set of said DNHL to store data.

19 . The cache controller of claim 15 wherein said set and way identifiers identify a set and a way of said special cache.

20 . The cache controller of claim 15 wherein said special cache stores addresses in home and non-home locations.

21 . A method of invalidating a DNHL way other than that which stores an identifier of a most accessed special cache location, said method comprising:
determining a set of a DNHL that tracks a non-home location of an address in a special cache; if none of one or more locations of said set of said DNHL are available for storing an identifier of said non-home location, determining which of said one or more locations has been most accessed; and invalidating a location of said set of said DNHL other than said one or more locations of said set of said DNHL that has been most accessed.

22 . The method of claim 21 wherein said determining comprises identifying a set of said DNHL that is designated to track a set of said special cache that contains said location of said special cache.

23 . The method of claim 21 wherein each location of said set of said DNHL is associated with a counter.

24 . The method of claim 21 wherein said determining which of said one or more locations has been most accessed includes examining a counter associated with said one or more locations.

25 . The method of claim 21 wherein said invalidating frees a way of said set of said DNHL to store data.

26 . The method of claim 21 wherein said special cache stores addresses in home and non-home locations.

27 . The method of claim 21 wherein each set of said DNHL comprises a plurality of ways.

28 . A processor system, comprising:
processing components; and cache controlling components, wherein said cache controlling components comprises a system for invalidating a DNHL way other than that which stores an identifier of a most accessed special cache location, said method comprising: a determining component for determining a set of a DNHL that tracks a non-home location of an address in said special cache; a determining component for, if none of one or more locations of said se

Assignees

• Soft Machines Inc

Inventors

• Avudaiyappan Karthikeyan

Classifications

• G06F12/0824

  Distributed directories, e.g. linked lists of caches · CPC title

• G06F12/0833 Primary

  in combination with broadcast means (e.g. for invalidation or updating) · CPC title

• G06F2212/601

  Reconfiguration of cache memory · CPC title

• G06F12/12 Primary

  Replacement control · CPC title

• G06F2212/1044

  Space efficiency improvement · CPC title